Researchers at our institute, under the direction of dr. Anna Ogrodowczyk used the freeze-drying process to create an unusual yogurt. The herbal and honey addition will make the product distinct and highly digestible. How does it differ from commercially available products?

Freeze-drying is a multi-step process, and in the simplest terms, it involves the removal of water from a frozen product by sublimation of ice, i.e., transformation into water vapor bypassing the liquid state. It is often referred to as the space method of food preservation because astronauts use it. It was used as early as the Incas. However, the first modern use of freeze-drying technology was in 1906 when Fréderic Bordas and Jacques-Arsène d’Arsonval showed that it was possible to dry frozen delicate and temperature-sensitive blood serum.

Today, freeze-dried foods are highly valued in the kitchen because they preserve all nutrients and flavor. Most importantly, freeze-dried products are highly durable – the shelf life under proper conditions is three years, although, in reality, it can be up to 10 times longer (as long as it remains dry). It was the freeze-drying method that dr. Anna Ogrodowczyk of the Department of Food Immunology and Microbiology, whose research project „Yogurt from the Garden with honey and freeze-dried herbs” was implemented under the „Innovation Incubator 4.0” program, decided to rely on. We asked dr. Ogrodowczyk about what is unique about the yogurt she developed and who might like it most.

What is unusual about the yogurt developed by your research team?

Dr. Anna Ogrodowczyk: What is new is the addition of freeze-dried herbs from the buttercup and nettle family. The herbal raw material is no novelty, but it is not usually combined with dairy products, much less honey. The choice of freeze-drying as a technology for preserving herbs has been proposed because of its ability to maximize the preservation of herbs’ natural color and aroma, which is impossible with conventional elevated-temperature drying processes. Drying herbs at room temperature is generally an efficient process. Still, due to the delicate structure of the leaves, the thin flesh and skin, and the glandular hairs in the skin, aroma-forming substances evaporate quickly. It has been scientifically confirmed that freezing and freeze-drying herbs most effectively fix their essential oils. The process is just as efficient as chemical extraction, but none of the solvents and complex procedures are used in extract and aroma production. Freeze-drying also results in a significant concentration of the raw material because, unlike drying, only 1-2% of water is left in the raw material, while 10-15% is left in the dried.

How does this affect the taste of the yogurt itself?

AO: Herbs’ natural flavor and aroma are faithfully preserved – even concentrated. It is the herbs that will be the primary substance shaping the taste and smell of the product. Also new is the absence of fruit additives. It is a different product and certainly intensely „herbal.” It will be appreciated especially by supporters of more dry products and those who enjoy what is ours – Polish and straightforward. This is because all the raw materials used are local, also alluded to by the name Yogurt from the Garden.

Why the addition of honey?

AO: It will serve as an added sweetener in the product. Honey is characterized by its sweet yet mild taste, so you can add less of it compared to other sweeteners and still maintain the definite taste of the product. Unlike sweeteners, there is no lingering impression of a biting aftertaste, and it is given a high overall rating in most sensory tests. The addition of honey will be optional for consumers – we are also developing variants that will lack it.

What products will hit the market?

AO: Our product is a composition of herbs and honey for dairy products. The versatility of this additive is a phenomenon we are studying in terms of implementation potential. Such an additive could be implemented by selling raw materials for home yogurt production, for artisanal yogurt production, such as for restaurateurs and hotels, as well as in dairy production in small and medium-sized enterprises.

Who will be tempted by Yogurt from the Garden?

AO: Yogurt from the Garden will be a product aimed mainly at adult consumers concerned about the environment. The use of local raw materials and additives will reduce the carbon footprint. The use of exotic fruits and spices will also be omitted, and the products, thanks to the addition of herbs, will provide a light and refreshing dietary alternative to traditional sweet fruit yogurts – especially during the summer season.

The project implemented under the „Innovation Incubator 4.0” program, financed by MEIN, is from European funds under the project „Support for scientific research management and commercialization of R&D results in scientific units and enterprises” under the Operational Program Intelligent Development 2014-2020 (Measure 4.4).